What significance do you see in the strand of iron-gray hair on the second pillow in "A Rose for Emily"?
By the time that the story wraps up, Emily is an old woman, with iron-gray hair. The significance of the hair on the pillow in the attic is huge. It implies that Emily, recently, was lying down or sleeping next to the rotted remains of Homer Barron. If you just think about that for a while, its creepiness really sinks in. First of all, she wasn't super old when he "disappeared", so one has to wonder how long she has been sleeping next to the dead body. Secondly, what kind of delusions, insecurities, and psychoses would lead a woman to do that? You have to wonder at her state of mind, and what sort of satisfaction or fulfillment she derived from that activity.
Faulkner has the reader of the story use inference, or educated guessing, as to what the significance of that hair is. If you look at the clues throughout the book (she's older, Homer disappears, the house starts to smell, and how at the beginning of the story she didn't want people to take her dead father away), one can infer that she killed Homer, stashed him in the attic, and has been deriving some sort of disturbing comfort from resting next to his dead body. Fun stuff, indeed! I hope that helps!